Electrical connecting and switch device



Sept. 27, 1966 G, D. FERDON ETAL 3,

ELECTRICAL CONNECTING AND SWITCH DEVICE 2 Sheets-Sheet 1 Filed Jan. 10,1964 Illlllll' p 27, 1956 G. D. FERDON ETAL 3,275,765

ELECTRICAL CONNECTING AND SWITCH DEVICE Filed Jan. 10, 1964 2Sheets-Sheet 2 United States Patent Ofiice 3,275,765 Patented Sept. 27,1966 3,275,765 ELECTRICAL CONNECTING AND SWITCH DEVICE Gilbert DouglasFerdon and Homer Ernst Henschen,

Cariisle, Ia, assignors to AMP Incorporated, Harrisburg, Pa.

Filed Jan. It), 1964, Ser. No. 337,095

2 Claims. (Cl. ZOO-51.1)

This invention relates to disengageable connecting and switch devicesfor electrical conductors.

It is an object of the invention to provide an improved disengageableelectrical connecting device for relatively small diameter wires. Afurther object is to provide a disengageable connecting device which isof extremely small size and which has a high degree of invulnerabilityto damage during routine handling. A further object is to provide asmall size contact terminal for electrical conductors which has exposedcontact surfaces for care of electroplating, these contact surfaces alsobeing protected from damage or contamination during handling. A furtherobject is to provide disengageable contact terminal means for smalldiameter wires having a relatively simple and durable contact springwhich achieves a predetermined reproducible contact pressure betweencontact terminals. A still further object is to provide a disengageableconnecting device for two groups of electrical conductors whichfunctions also as a switching device for forming circuit paths amongconductors belonging to the same group and alternatively betweenpredetermined conductors of the two groups.

These and other objects of the invention are achieved in a preferredembodiment comprising a pair of substantially identical connectingblocks, each of which has a plurality of contact cavities extendingtherethrough. Contact terminals which are secured to the ends of wiresare disposed in the cavities of each block, each terminal having achannel-shaped cross-section with the inside surface of the channelfunctioning as a contact surface. The connector blocks are each adaptedto be mated to a connecting block having leaf springs therein in amanner such that when the two connector blocks are engaged with theconnecting block, each leaf spring engages the contact surface of twocontacts, one of which is in each of the connector blocks. The springsthus function as conducting bridges between the contact terminals in thetwo connecting blocks.

The invention also contemplates the formation of circuit paths extendingbetween two individual conductors in one group or bundle of conductorswhen only one of the connector blocks is mated to the connecting block.A circuit path of this type is established by means of a shunt devicewhich electrically connects two individual contact springs mounted inthe connecting block. The arrangement is such that when the secondconnector block is brought into engagement with the connecting block,the shunt is deactivated and the circuit path connecting the twoindividual conductors in the first group or bundle is interrupted. Atthe same time, one of these conductors is electrically connected to anindividual conductor in the second group of conductors.

In the drawing:

FIGURE 1 is a perspective view of a preferred form of contact terminalin accordance with the invention.

FIGURE 2 is a plan view of a contact spring for forming a disengageableconnection between terminals of the type shown in FIGURE 1.

FIGURE 2A is a side view of the spring of FIGURE 2.

FIGURE 3 is a perspective view of a complete connector assembly inaccordance with the invention comprising a pair of connector blockshaving contact terminals mounted therein and a connecting block havingcontact springs mounted therein, one of the connector blocks beingengaged with, and the other connector block being disengaged from, theconnecting block.

FIGURE 4 is a sectional side view of the connector assembly of FIGURE 3.

FIGURE 5 is a sectional side view of an alternative embodiment of theinvention which achieves a switching function among conductors of onegroup or bundle as well as a connecting function between conductors ofone group and conductors of a second group.

FIGURE 5A is a perspective view of a blank insulating insert used in theembodiment of FIGURE 5.

FIGURE 6 is an end View of the connecting block used with the embodimentof FIGURE 5.

FIGURE 7 is a perspective view of a shunt clip used with the embodimentof FIGURE 5.

A preferred form of contact terminal 2 in accordance with the inventionis of channel-shaped cross-section and has sidewalls 4 at its rearwardend which are crimped onto the stripped end of a wire positioned betweenthese sidewalls. Intermediate its ends, a pair of tongues 8, 14 arestruckup from the web, the tongue 8 extending substantially normally ofthe web adjacent to the ferrule forming sidewall portions 4 andproviding a forwardly facing stop surface 9 for engagement with a bossin the connector block as described below. The tongue 14 is containedbetween the forward sidewall portions 1t of the terminal and slopesrearwardly from the plane of the web to provide a rearwardly facing stopsurface 12. The portion 16 of the web which lies in front of the tongue14 functions as a contact surface as described more fully below and thesidewalls advantageously extend forwardly beyond the end of the web andare bevelled on their inner sides as shown at 20 to facilitate the entryof a mating contact member. The leading edge of the web portion 16 issimilarly bevelled on its upper side as shown at 18 for ease ofengagement and disengagement.

A pair of contact terminals of the type shown in FIGURE 1 are adapted tocooperate with a connecting leaf spring 22 having a central fiat section24 and downwardly curved contact end portions 34 which advantageouslyare reversely curved towards the plane of the web at the extreme ends ofthe spring as shown at 31. Ears Z6, 27 are provided on each side of theflat central section 24 extending from the edges thereof, the ears 25being disposed in alignment with each other on one side of the center ofthe spring and the ears 27 being disposed on the opposite side of thecenter. The opposed edges 29, 30 of these cars cooperate with bosses ina con necting housing as described below to retain the contact spring ina cavity.

A connector assembly in accordance with the invention (FIGURES 3 and 4)comprises two substantially identical connector blocks 32, 34 and acentral connecting block 42 with which the connector blocks areengagea-ble. Each connector block has a plurality of cavities 36extending therethrough which are dimensioned to receive a contactterminal 2. An intermediate boss 38 extends from one wall of each cavityfor cooperation with the stop surfaces 9, 12 of the terminal to retainthe terminals in the cavities. It will be apparent that after crimping aterminal onto a wire 52, the terminal can be inserted into one of thecavities 36 until the stop surface 9 is moved against the rearwardlyfacing side of the boss 38. The tongue 14 will be deflected duringinsertion but will return to its normal position after the end of thetongue has passed the boss 38 so that the edge 12 of the tongue willfunction to prevent any rearward movement of the terminal. The length 3of the blocks 32, 34 is such that the forward ends of the contactterminals project beyond the mating face 39 of the block and arecontained within a hood portion on the forward end of the block.

The connecting block 42 has an enlarged central section 44. and reducedcross section end portions 46 which conform to the interior surfaces ofthe hoods it? of the connector blocks. Cavities 48 extend longitudinallythrough the connector block, each cavity having a central boss 59 on oneof its Walls which is adapted to lodge between the opposed edges 29, 3dof the ears of a contact spring 22. The curvature of the end portions30, 31 of the contact springs 22; relative to the height of the cavities48 is advantageously such that when an individual spring is insertedinto a cavity, the curved ends will be plastically (i.e., permanently)deformed and after insertion the undersides of the ends 30 will bearagainst the floor of the cavity 48 and bias the cars 26, 27 upwardlyagainst the top surface of the cavity. adhered to, the individualsprings will be set when they are inserted into a cavity and the forceexerted by the ends of the springs against the floor of a cavity will begenerated by the spring-back efiect in the spring. This arrangementassures a uniform contact pressure for all of the springs since thisspring-back effect is highly predictable and reproducible when thecavity dimensions and the spring materials are maintained constant.

In use, an electrical connector assembly is formed by merely insertingappropriate contact terminals into cavities of a pair of connectorblocks 3.2, 34 and the electrical connections are formed by merelymating each connector block with the connecting block 42. Connectingdevices in accordance with the invention are partiularly intended forrelatively small sized wires, for example, AWG 28-32. Where wires ofthis size range are involved, it is apparent that an extremely smalldisengageable connecting device must be used since the associatedelectrical apparatus will itself be reiatively small and there will besevere space limitations imposed on the connecting devices used.

Although the connectors used for small diameter conductors must berelatively small, they must nonetheless satisfy the performance criteriagenerally applied to high quality electrical connectors of larger sizesand must, in fact, be relatively superior to connectors for largerdiameter wires in at least some respects. For example, the contactterminals themselves should be capable of withstanding normal handlingabuse during crimping and insertion, must be capable of having theircontact surfaces plated since gold plating is usually employed on thebetter quality contact terminals, and finally must be capable of a levelof electrical performance consistent with the intended usage. Electricalperformance in the case of miniature contact terminals is of particularimportance for the reason that where small diameter wires are employed,the voltages and currents involved are usually quite low so that theresistance imposed on the circuit by the terminal must be extremely low.Where larger wires, for example AWG 18, are being used the currentandvoltage conditions will be relatively higher and a somewhat highercontact resistance in the terminal can be tolerated.

By virtue of its channel-shaped cross-section, the disclosed type ofterminal can be made of relatively thin stock (for example 0.008" thick)but will be extremely rigid and resistant to damage. The contactsurfaces 16 can be plated with gold or other noble metal with case sincethey are expose to the eledctroiyte in a plating bath; at the same timethese contact surfaces are protected against contamination duringhandling since they are protected on each side by the sidewall portionsit) of the terminal. The contact pressure generated at the interfacebetween the ends 30 of the springs and the contact terminals is uniformand controllable for the reason, explained above, that the contactsprings are If these relative dimensional relationships are set whenthey are inserted into the connecting block and generate their contactpressure as a result of their predictable and reproducible spring-backproperties.

Referring now to FIGURES 57 under some circumstances it is desirable toestablish circuit paths among individual conductors in the group A ofwires which are crimped onto terminals mounted in the connector housing32' when this group of wires is not connected to the conductors in thegroup B, that is when the connector housing 34' is disengaged from theconnecting housing 42. Under these circumstances it is usually desirableto break the electrical connection between and among the conductors ofwire group A when these wires are connected to their intendedcounterparts in wire group B. This effect can be achieved by means ofthe embodiment of the invention shown in FIGURES 57 in which themodified connecting housing 42 has adjacent cavities 48', 48 in whichcontact terminals extending from conductors 62, 64 of wire group A arelodged. The wall 49' which separates the cavities 48 and 48" is ofreduced thickness on its left-hand side as shown at 54 and a shunt clip(FIGURE 7) of brass or other conducting metal is fitted over thisreduced thickness end section of the wall. This clip 56 is of U-shapedconfiguration and has relatively elongated sides 53 of arcuatecross-section. Sides 58 have spurs 60 extending from their edgesadjacent to their free ends so that the clip can be assembled to thewall section 54 by merely being slipped over the end of the wall andflattened against the surface thereof until the arcuate legs bearagainst the surface and the spurs dig into the wall material. The shuntclip functions as a conducting path between the contact ends of thesprings in the cavities 43, 48 when the connector 34' is disengaged fromthe connecting housing 42 so that under these circumstances a conductingpath will extend from the conductor 62 to the spring in the cavity 48',through the clip 56 and thence to the spring in the cavity 48 and to theconductor 64.

The connector block 34 has cavities 51, 53 extending therethrough whichare in alignment with the cavities 48', 4-8" of the connecting block42'. A contact terminal 2 which is crimped to a conductor 66 ispositioned in the cavity 51 while an insert 70 is positioned in thecavity 53. The insert 76 comprises a blank composed of a suitableplastic insulating material, such as polycarbonate, having the samegeneral shape as the contact terminals 2. When the connector block 3 isengaged with the connecting block 42', the insert blank '70 movesbetween the lower surface of the shunt clip 56 and the contact spring inthe cavity 48" thus interrupting the circuit path connecting the wires62, 64. At the same time, the contact terminal 2 in the cavity 51 ofblock 34' moves into engagement with the contact spring in the cavity48' thus establishing a circuit path connecting the conductor 62 and 66.

FIGURE 5 shows one possible switching arrangement which can be achievedby means of a specially designed connecting housing 42' used inconjunction with a pair of standard connector housings 32,, 34 and oneinsert blank 70. The connecting block 42, has two rows of cavities 48,48" and the wall sections 2-9 between the upper and lower rows ofcavities can be of reduced thickness in one of more instances with shuntclips 56 fitted over each of these wall sections. It follows that anumber of possible switching combinations can be achieved by usingstandard connector blocks along with one specially constructedconnecting block as regards the thickness of the wall sections 54between the rows of cavities.

As an alternative, the connecting block can be provided with reducedwall sections between each pair of cavities and clips similar to theclip of FIGURE 7 but composed of an insulating material, for example,polycarbonate can be supplied, as weil as metallic clips. Where aswitching eflfect is desired between conductors, a metallic clip wouldbe positioned over the reduced wall section 54 between pairs of cavitiesto achieve the result of FIGURE 5. If a switching effect is not desired,an insulating type clip can be mounted on the reduced diameter wallsections to form conventional disengageable connections between pairs ofconductors.

Change in construction will occur to those skilled in the art andvarious apparently difierent modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

I claim:

1. A multi-contact electrical connecting device comprising: a pair ofconnector housings and a connecting housing, said connector housingseach having a hood surrounding, and extending beyond, one end thereof,said connecting housing having opposite ends conforming to the internalconfiguration of said hoods whereby, said connector housings can becoupled to, and decoupled from, said connecting housing, a plurality ofcontact terminal cavities extending through each of said connectorhousings, contact terminals in at least some of said terminal cavities,said terminals each having a contact portion of channel-shapedcross-section disposed within the confines of said hoods, saidconnecting housing having contact spring cavities extending between saidopposite ends, contact leaf springs disposed within said contact springcavities, the ends of said leaf springs being engageable with saidcontact portions of said contact terminals upon coupling of saidconnector housings to said opposite ends of said connecting housingthereby to form conducting paths between individual conductors securedto said contact terminals, shunt means in said connecting housingextending from a first one of said contact spring cavities to a secondone of said contact spring cavities, said shunt means normally being inengagement with the contact leaf springs in said first and secondcontact spring cavities whereby, a continuous conducting shunt path isestablished between two conductors secured to contact terminals in oneof said connector housings when said one connector housing is coupled tosaid connecting housing, and shunt circuit interrupting means in acorresponding contact terminal cavity in the other one of said otherconnector housings, said shunt circuit interrupting means beingengageable with said shunt means for deactivating said shunt means whensaid other connector housing is coupled to said connecting housingthereby to break said conducting shunt path and to establish aconducting path between two corresponding contact terminals in saidconnector housings.

2. A device as set forth in claim 1 wherein said shunt circuitinterrupting means comprises an insert blank in said correspondingcontact terminal cavity, said insert blank being of an insulatingmaterial and being movable between said shunt means and one of saidcontact springs.

References Cited by the Examiner UNITED STATES PATENTS 1,825,208 9/1931Rumble 20051.1 X 2,924,807 2/1960 Field. 3,065,440 11/1962 Bonwitt et al339-19 X 3,069,682 12/1962 Reese 33919 X 3,149,893 9/1964 Dupre 33919 XFOREIGN PATENTS 463,631 7/1928 Germany.

ROBERT K. SCHAEFER, Primary Examiner.

D. SMITH, JR., Assistant Examiner.

1. A MULTI-CONTACT ELECTRICAL CONNECTING DEVICE COMPRISING: A PAIR OFCONNECTOR HOUSINGS AND A CONNECTING HOUSING, SAID CONNECTOR HOUSINGSEACH HAVING A HOOD SURROUNDING, AND EXTENDING BEYOND, ONE END THEREOF,SAID CONNECTING HOUSING HAVING OPPOSITE ENDS CONFORMING TO THE INTERNALCONFIGURATION OF SAID HOODS WHEREBY, SAID CONNECTOR HOUSINGS CAN BECOUPLED TO, AND DECOUPLED FROM, SAID CONNECTING HOUSING, A PLURALITY OFCONTACT TERMINAL CAVITIES EXTENDING THROUGH EACH OF SAID CONNECTORHOUSINGS, CONTACT TERMINALS IN AT LEAST SOME OF SAID TERMINAL CAVITIES,SAID TERMINALS EACH HAVING A CONTACT PORTION OF CHANNEL-SHAPEDCROSS-SECTION DISPOSED WITHIN THE CONFINES OF SAID HOODS, SAIDCONNECTING HOUSING HAVING CONTACT SPRING CAVITIES EXTENDING BETWEEN SAIDOPPOSITE ENDS, CONTACT LEAF SPRINGS DISPOSED WITHIN SAID CONTACT SPRINGCAVITIES, THE ENDS OF SAID LEAF SPRINGS BEING ENGAGEABLE WITH SAIDCONTACT PORTIONS OF SAID CONTACT TERMINALS UPON COUPLING OF SAIDCONNECTOR HOUSINGS TO SAID OPPOSITE ENDS OF SAID CONNECTING HOUSINGTHEREBY TO FORM CONDUCTING PATHS BETWEEN INDIVIDUAL CONDUCTORS SECUREDTO SAID CONTACT TERMINALS, SHUNT MEANS IN SAID CONNECTING HOUSINGEXTENDING FROM A FIRST ONE OF SAID CONTACT SPRING CAVITIES TO A SECONDONE OF SAID CONTACT SPRING CAVITIES, SAID SHUNT MEANS NORMALLY BEING INENGAGEMENT WITH THE CONTACT LEAF SPRINGS IN SAID FIRST AND SECONDCONTACT SPRING CAVITIES WHEREBY, A CONTINUOUS CONDUCTING SHUNT PATH ISESTABLISHED BETWEEN TWO CONDUCTORS SECURD TO CONTACT TERMINALS IN ONE OFSAID CONNECTOR HOUSINGS WHEN SAID ONE CONNECTOR HOUSING IS COUPLED TOSAID CONNECTING HOUSING, AND SHUNT CIRCUIT INTERRUPTING MEANS IN ACORRESPONDING CONTACT TERMINAL CAVITY IN THE OTHER ONE OF SAID OTHERCONNECTOR HOUSINGS, SAID SHUNT CIRCUIT INTERRUPTING MEANS BEINGENGAGEABLE WITH SAID SHUNT MEANS FOR DEACTIVATING SAID SHUNT MEANS WHENSAID OTHER CONNECTOR HOUSING IS COUPLED TO SAID CONNECTING HOUSINGTHEREBY TO BREAK SAID CONDUCTING SHUNT PATH AND TO ESTABLISH ACONDUCTING PATH BETWEEN TWO CORRESPONDING CONTACT TERMINALS IN SAIDCONNECTOR HOUSINGS.